1. Technical Field
The present disclosure relates to a trocar assembly for use in minimally invasive surgical procedures, such as endoscopic or laparoscopic type procedures.
2. Background of the Related Art
Minimally invasive procedures are continually increasing in number and variation. Forming a relatively small diameter temporary pathway to the surgical site is a key feature of most minimally invasive surgical procedures. The most common method of providing such a pathway is by inserting a trocar assembly through the skin. In many procedures, the trocar assembly is inserted into an insufflated body cavity of a patient. In such procedures, the trocar assemblies with seal mechanisms are utilized to provide the necessary pathway to the surgical site while minimizing leakage of insufflation gases.
Trocar assemblies typically include an obturator which is removably inserted through a cannula. The obturator may include a safety shield which protects against unintentional puncturing by the sharpened tip of the obturator. The safety shield includes a mechanism which controls the relative movement and locking of the safety shield. One example of a safety shield mechanism is disclosed in commonly assigned U.S. Pat. No. 6,319,266 to Stellon et al., the entire contents of which are hereby incorporated by reference.
Insertion of the trocar assembly through the body wall of the patient can require the application of significant axial force. Typically, during the procedure, the obturator housing is grasped and pressure is applied to the assembly. In addition to application of pressure, the surgeon may rotate the obturator housing, either intentionally or unintentionally, to pass the penetrating tip through the tissue. However, any torquing of the obturator housing may be undesirable, particularly, with an obturator having a flat bladed tip. As rotation of the flat bladed tip may cause undesired tearing of tissue.
Accordingly, there is a need for further improvement in trocar obturator assemblies including assemblies which reduce undesirable tearing of tissue.